Since the development of photovoltaic solar cell, many kinds of solar cell itself and methods of assembling the cells into a module, including the methods of assembling the solar cells for mounting on a house roof, have been introduced. Those methods teach only how to assemble each solar cell and the parts to connect them in a planar shape. According to those illustrations, lots of heavy metal parts and ceramic insulators are necessary to make whole solar cell modules for mounting them on a roof of a house. The final solar cell module for a house may too heavy for the roof of a house. The heavy weight of the module limits the number of module plates installed on a roof and the magnitude of the power that can be obtained from them. In addition, it is not easy to clean the surface of the module plates. So, the efficiency of generating electricity is easily decreased due to the polluted air and dusts of big cities. It is the purpose of the current application to eliminate such limits.